The Emerging Role of Microfluidics in Multi-Material 3D Bioprinting
Biofabrication technologies, such as 3D bioprinting, have been gaining the interest of researchers in the field of tissue engineering over the past few decades. Although many advancements have been made in the field, in order to push 3D bioprinting technology from simple lab-based tissue fabrication, to fully functional and implantable organs, the technology must not only provide shape control, but functional control. This can be accomplished by replicating the cellular composition of the native tissue at the microscale. There is therefore a need for precise, controllable, multi-material printing that could allow for single cell resolution. This paper aims to draw attention to technological advancements made in 3D bioprinting that target the lack of multi-material, and/or multi celltype, printing capabilities of current devices. Unlike other reviews in the field, which focus solely on variations of single-material 3D bioprinting involving the standard methods of extrusion-based, droplet-based, laser-based, or stereolithographic methods, this review accentuates multi-material 3D bioprinting using multi-cartridge printheads, co-axial nozzles and microfluidic-enhanced printing nozzles.